Cartridge



sept. 2o, 1949.v

R. R. STUDLER ET AL CARTRIDGE Filed March 1o, 1943 Rane R- Etudler' Samuel Faltman Charle E.Ela1le'15en alen'ted Sept. 2Q, 1949 CARTRIDGE Ren R. Studler, Washington, D. C., Samuel v Feltman, Arlington, Va., and Charles E. Balleisen, Philadelphia, Pa..

Application March 10, 1943, Serial No.v 478,660 1 Claim. ((1102-38) (Granted under theA act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) The invention described herein may .be manufactured and used by or for the Government for governmental purposes rwithout the payment to us of any royalty thereon.

This invention relates to projectiles for lrearms, and more particularly, to the type of projectile having a'jacket usually of copper or other non-ferrous material the outside diameter of a major portion of which measures to the calibre of the firearm but which is provided with a smaller portion or portions of a diameter larger than the barrel calibre at the gun muzzle. This enlarged jacket portion or portions is reduced during its passage through the tapered bore of the gun, by a crushing action upon the comparatively soft jacket material, down to the actual muzzle calibre; for this purpose, the gun barrel has a section following the breech and cartridge section, of suicient diameter to receive the enlarged jacket portion or portions. The gun barrelis reduced or tapered, in one or more stages, from the said enlarged section to the gun calibre at the muzzle.

rhe range and momentum of the projectile depends chiefly upon the pressure developed upon the explosion of the propellant and the area of the projectile presented to that pressure. In the ordinary type of projectile of outside diameter equal to that of the gun calibre, the effective area is the cross-sectional area corresponding to the outside diameter of the jacket. This area cannot be enlarged, for ballistic reasons: the air resistance and other effects and forces present in ilight increases with increase in projectile 'diameter (calibre). In the type of projectile referred to, additional area to receive the pressure engendered by the explosion is provided by the enlarged portions of the jacket, As stated above, this enlarged jacket portion is reduced during passage through the bore of the barrel down to the gun calibre, so that no part ofthe enlarged jacket will be .present during flight.

One of the objects of this invention is to provide animproved projectileof the type referred to. How the projectile is improved will 'be apparent from the accompanying drawings; wherein:

Figure 1 is a longitudinal section through one form of improved projectile in position in its cartridge shell; Y

' Figure 2 isa longitudinal section of the projectile of Figure l in flight;

Figure 3 is a longitudinal section through another form of improved projectile in position in its cartridge shell;

Figure 4 is a longitudinal section of the j ectile of Figure 3 in ight;

Figure 5 is a cross-sectional View on line 5-5 of Figure3; and

Figure 6 is a diagram of the forces acting upon a projectile in flight.

The invention is illustrated in Figures 1-2 and Figures 3 4-5, in connection with armourpiercing projectiles, which diiier from ball projectiles in the nature Yof the core, the core in both casesV being contained in a suitable jacket such as copper, brass of gilding metal: The core in the common ball projectile is lead, whereas heat treated steelis used in armour-piercing projectiles. The core in Figures 1-2 and the core 20 in Figures 3-4-5 Vrepresent'heat-treated steel suited for armourpiercing purposes. The projectile may comprise only core and jacket as in the species of Figures 3-4-5 or it may have, in addition,'a point filler" -9 of lead as in Figures 1-2. It should be understood, however, that the invention may be applied to ball (lead core) projectiles.

The jacket of Figures 1-2 is constructed Yof two pro'- sections, a main section l0 and a considerably smaller section I9 at the nose'of the projectile which might Vconveniently be termed the windshield cap. The right end of main jacket I0 is bellied out toA form an annular rib Il which is readily Afabricated from the regularly-shaped jacket by rst cutting the same to form the said two parts (main jacket I0 and windshield cap I9) and then flanged to form the annular rib Il. As clearly seen in Figure 1, the free edge Ile of the anged rib II makes contact with the surface of core 20,A andis removed from the edge of Ythe windshield cap I9 by a clear space, designated I.

'I'he left or rear end portion of the jacket is formedas a skirt I3 Aof enlarged diameter, equal to the diameter of the annular rib I I. The jacket portion between skirt I3 and rib II-i. e., the Waist portion I 2-is soldered or sweated 22 to core 20; to ensure a rm securement the core may be knurled or otherwise roughened.

The area of the projectile effective toreceive the explosiveV pressure ls thus increased from diameter f which it would have in ordinary projectiles to enlarged diameter e. During its pas-A sage through the barrel of the gun, the annular rib II and 'skirt' I3 are reduced down, in the manner ekplained above, to the uniform diamserves two functions, viz., (a) the one just men-V-Y tioned in the flattening operation, and (b) to prevent twisting of the jacket on the core during the riing of the jacket as the projectile passes through the rifling portion-ofthe barrel. The skirt portion I3 is reduceduor'4 deformd'dwn" to` uniform diameter f as shown in Figure 2.

For the purpose of presenting arlL enlargedv area to the propellant pressure either the skirt I3 or annular rib I I would suiice. Botharused for a further reason, namelyfftoprovide two points of support for the projectile during-fits"Y passage through the enlarged part of the gun barrel, and thus to eliminate lateralor sidewise movement of the projectile, which would be` possible` were a shorter base of contact provided.V The cartridge shell, part of which (8) is shown in the figures, is clipped at 1 over the beveled portion |317 of the skirt (see Figure 1). Y

vIt will be observed from Figure 1 that the skirt I3 extends a short distance to the rear of core 20. After the reducing down of the jacket in its passage through the gun, i. e., when the projectile is in flight, this skirt extension will be somewhat increasedpthe skirt extension is designated |33: in Figure 2. The purpose of skirt extension |332.. will be explained with the aid of Figure which showsthe forcesv acting upon a projectile in Iiight. These forcesA are chiefly, in addition of course, to the momentum of the projectile, the forcerof gravity W acting upon the center of gravity y and the resultant forces due to relative wind resistance R which actsupon a. point p known as the center of pressure, which is` always displaced a considerable distance awayVV from the center of gravity. As a result thereof, a torque or couple is-created,` being the resultant force R at the distance arm between y and p depending upon theposition or displacement of the resultant force. ThisY couple tends to cause the projectile vto turnin its flight` about point. g (through angle a). It is a. desideratun, therefore, to bringthe center of pressure p as close vas possible to the center of gravity y in order. to keep the aforesaid couple as small as possible.

This is achieved in the improved. projectile of Figures 1-2 by extending the jacket alone, by means of its skirt extension I3znwithout increasing the length of coreZll.. The increased surface presented to the windat the rear (left in Figures 1-2) of the projectile causes the center of pressure of the projectile to be broughtA further to the rear of the projectile and hence closer to the projectiles center of gravity.

The projectile of Figures' 3---5 differs from that of Figures 1-2 in that, instead of two points'. of support afforded by skirt I3 and' Aannularr rib I I (thus constituting an effective base from point' I3 to point Il), a single base is provided. As' Shown in Figure 3, the rear of jacket 40 is enlarged to form a bulbous portion` 42 connected to the front jacket portion by a bevel" 4I.` The bulbous portion 42 extends over a considerable" part of the core to afford a sufficient base functioning in the projectiles passage through the'A barrel, as explained above. The rear fend" of theA bulbous jacket 42 is provided with a ang'e 44 which projects normally and inwardly from cylindrical portion 42, through a curve or llet 43. The rear end of core 20` has a cupped depression 35; and the edges of flange 44 is pressed back at 4:55 toA bereeived at the periphery' of core cup 25. The distance between the flangeVA edges is designated d in Figure 3, the opening being circular (see Figure 5). The rear edge of the core is also rounded as indicated at 23.

The jacket may be secured to the core by sweating asv in-jthe coref Figures 1 2. The core 2|] has in addition,V one or more flats 2| which serve to prevent twisting of the core in its jacket. The cartridge shell 8; is clipped over the bevel 4I of bulbous jacket 42, at 1, Figure 3.

The rear end of bulbous jacket 42 has one orv more portvholes 46 to expel the air in the annular spacebetween jacket and core, when the bulbous part is flattened down. As shown in Figure 5, three such holes 46 are provided, symmetrically arranged as equally spaced from each other. Whenre'duced by passage through the gun, the'v bulbous portion will be entirely eliminated (see Figure 4), except for the rearinward flange 44, theedges 45 of which will touch, or almost'. touch, .as shown in Figure 4. It will be noted that the fillet 46 of the jacket flange, the rounded edge 23 ofthe core and the cupped depression 25 of the core, all aid in directing the bulb'ous jacket in a manner to more or less completely encase the. rear end of the core.

We' claim:

In a cartridge comprising a cartridge shell and av projectile of the type having a corel and a de'- formable jacket, a portion of which is of enlarged diameter receivable in the breech end of a gun` barrel, the said barrel having an initial section adapted to reduce the said enlarged jacket t6 the calibre. diameter at the muzzlel end of the barrel, the combination of a dual-sectioned jacket having a` main section and a shorter forward section at the projectile nose', the said main jacket being bellied out-near its forward en'd to form an annular rib of enlarged diameter, and provided with a skirt of substantially the said' enlarged diameter ofthe annular rib, a. portion ofv which extends beyond the rear end of the said coreithe: said annular rib andthe said skirt being' separated byv a reduced' waist portion in contact with the core, the said cartridge shell beingclipped to the annular flange provided at tlie juncture of the said waist and skirt portions of the jacket. Y ,A

RENER. STUDLER. SAMUEL FELTMAN. CII-IiLl'tIJESV E'. BALLEISEN.

REFERENCES CITED;

The following referencesY are of recordv intheI filer of tlflis-r pal-"tent:

UNITED STATES PllrrENTsv Number Name Date 693,534' Taylor Feb. 18, 1902- 1,669.,969 Caruth' May 15; 1928l 2,288,604 Born July 7, 1942- FOREIGN PATENTS Number Country Date I l18,601 Great Britain Y Y r 1904 521,633 Great Britain May127, 1944 

